A transmission device designed as a multi-gear planetary coupling transmission with several gearsets and several shift elements is known through DE 10 2007 005 438 A1. Depending on activation of the shift elements, different shift ratios can be created. At least an electric machine is provided which is in an operational connection with one of the planetary sets. Torque can be initiated by the electric machine in one of the planetary gear sets assigned to the electric machine through a shaft, to support another shaft at the assigned planetary set torque for creating a gear ratio in the planetary coupling transmission by way of the electric machine.
The electric machine replaces a load shift element, preferably designed as frictional connection in a conventional planetary coupling transmission, wherein by means of the electric machine, beside the transmission functions, such as load shifts, non-wearing start procedures and similar, also several hybrid functions, such as electro-dynamical, wear reducing start procedures, regenerative braking etc. are feasible. The hybrid functions which can be created with the electric machine are hereby dependent on the characteristics of the wheel set, as well as the power rating of the electric machine.
In addition, such a multi-gear planetary coupling transmission can be designed in different configurations, wherein a drive train of a vehicle which can be designed having a multi-gear planetary coupling transmission without a starting element, such as a hydrodynamic torque converter or a frictional contact starting clutch. In addition, a multi-gear planetary coupling transmission, which is designed with-instead of a shift element, with an electric machine, and can be designed with, instead of frictional contact shift elements, form-locking shift elements, as well as a reduced lubrication oil supply with a hydraulic gearset.
However, the disadvantage is herein that the planetary coupling transmission needs to be designed for the creation of a start-stop operation with a combustion engine and which is in an operational connection with a planetary coupling transmission, also requires an additional electric machine which increases the total weight of the vehicle and the manufacturing costs, and also requires and expands the construction space of the planetary coupling transmission to an unwanted size.